The irregular array's 5th row is [3,1]. The divisors of 6 are 1, 2, 3 and 6. In the 5th row there are 2 terms coprime to 1, 2 terms coprime to 2, 1 term coprime to 3 and 1 term coprime to 6. So the 6th row of the array is [2,2,1,1].